1. Technical Field
The present invention relates to a vehicle power supply device including a power storage device and a malfunction diagnosis method thereof.
2. Related Art
An electric vehicle which can be charged with an external power supply includes a hybrid electric vehicle (so-called plug-in hybrid) having an electric motor and an engine as power sources as well as an electric vehicle having only an electric motor as a power source. An in-vehicle charger is mounted on the electric vehicles to convert AC power into DC power, and power is supplied from an external power supply to a power storage device via the in-vehicle charger at the time of charging (see Japanese Unexamined Patent Application Publication (JP-A) Nos. 2008-289307 and 2012-85432).
During malfunction of the external power supply, however, power cannot be normally supplied to the in-vehicle charger and thus the electric vehicle generally detects charging abnormality and stops external charging. In addition, during disconnection of a power supply path connected to the in-vehicle charger, power cannot also be normally supplied to the in-vehicle charger and thus the electric vehicle also detects charging abnormality and stops external charging.
When the charging abnormality is detected by the electric vehicle as described above, a cause of the charging abnormality needs to be specified to appropriately cope with the charging abnormality. However during malfunction of an external power supply such as a household receptacle, it is difficult for the electric vehicle to grasp the malfunction state. Even during malfunction of the power supply path of the in-vehicle charger, it is difficult for the electric vehicle to grasp the malfunction state of the power supply path through which power is supplied only at the time of external charging.